During explosive forming, a work piece is arranged in a die and deformed by ignition of an explosive, for example, a gas mixture. The explosive is generally introduced to the die, and also ignited here. Two problems are then posed. On the one hand, the die and the ignition mechanism must be suitable to initiate the explosion in targeted fashion and withstand the high loads occurring during the explosion, and, on the other hand, good forming results with the shortest possible setup times must be repeatedly achieved.
In a method known from EP 0 830 907 for forming of hollow elements, like cans, the hollow element is inserted into a die and the upper opening of the hollow element closed with a plug. An explosive gas is introduced into the cavity via a line in the plug, which is then ignited via a spark plug arranged in the plug.
In a method described in U.S. Pat. No. 3,342,048, a work piece being deformed is also arranged in a die and filled with an explosive gas mixture. Ignition occurs here by means of mercury fulminate and a heating wire or filament. Both methods are particularly suitable for individual part manufacture and have not gained acceptance in practice for mass production.